Re: [PATCH v1 12/16] xen/domain: introduce domain-emu.h

[dmkhn@xxxxxxxxx]

On Fri, Aug 01, 2025 at 08:02:56AM +0200, Jan Beulich wrote:
> On 31.07.2025 22:55, dmkhn@xxxxxxxxx wrote:
> > On Wed, Jul 09, 2025 at 04:57:44PM +0200, Jan Beulich wrote:
> >> On 24.06.2025 05:56, dmkhn@xxxxxxxxx wrote:
> >>> @@ -458,16 +459,16 @@ struct arch_domain
> >>>  } __cacheline_aligned;
> >>>
> >>>  #ifdef CONFIG_HVM
> >>> -#define X86_EMU_LAPIC    XEN_X86_EMU_LAPIC
> >>> -#define X86_EMU_HPET     XEN_X86_EMU_HPET
> >>> -#define X86_EMU_PM       XEN_X86_EMU_PM
> >>> -#define X86_EMU_RTC      XEN_X86_EMU_RTC
> >>> -#define X86_EMU_IOAPIC   XEN_X86_EMU_IOAPIC
> >>> -#define X86_EMU_PIC      XEN_X86_EMU_PIC
> >>> -#define X86_EMU_VGA      XEN_X86_EMU_VGA
> >>> -#define X86_EMU_IOMMU    XEN_X86_EMU_IOMMU
> >>> -#define X86_EMU_USE_PIRQ XEN_X86_EMU_USE_PIRQ
> >>> -#define X86_EMU_VPCI     XEN_X86_EMU_VPCI
> >>
> >> The old code deliberately used values from the public interface.
> >
> > In next version I am building, I moved all of XEN_X86_EMU_XXX definitions as
> > is to a new public header under include/public/xen-emu.h:
> >
> >   
> > https://gitlab.com/xen-project/people/dmukhin/xen/-/commit/9b0bc5ffa5710114df8523ae2aa7680b7c6f0942
> >
> > That looks less invasive.
> >
> > Will that work?
> >
> > There should be a common header with emulation flags somewhere, since
> > there will be SBSA and hwdom vUART definitions there.
> 
> Yet will there be a strict need for any constants to be identical (i.e.
> not only have the same name, but also the same value) across architectures?

I don't think there's strict need for identical values across achitectures.
But some of the constants _may_ be reused for non-x86 arches, like VPCI bit
and, perhaps, IOMMU, PIRQ and future NS16550 (after adding MMIO).